to edit (from Viewer to Timeline) audio or video only:
use the target/destination tracks
i can't remember the shortcuts!
from memory Shift + F6 for V
Shift + F7, F8 for A1, A2
but look for destination" in the customise keyboard window
OR
for overwrite edits only, just LOCK the A or V tracks (wont work for Insert edits)
to select in the Timeline (dont know what you mean by "marque", marked w in/outs perhaps?)
use auto select buttons
Apple + number pad for V tracks (zero is all or none, 1-8 for V1-8)
Option + number pad for A tracks (zero is all or none, 1-8 for A1-8)
nick